probsoln package versions:

Version 3.0: Rewrote package to use data sets to make it easy
to reuse problems so that the solutions can be placed in 
a different section of the document to the questions.

Version 2.04: fixed license text

Version 2.03: Added starred form of \newproblem for problems without
solutions. Checks to see if solution environment is already defined.

Version 2.02: Added \selectallproblems which selects all the problems
in a given database, in the order in which they were defined.

Version 2.01: Provided means to customise the way in which randomly
selected problems are displayed. Added \doforrandN command (like \@for
but for a random subset of the specified list.) Added \random command
which stores a random number in the given range in the specified 
counter.